On 1/13/25 10:15 PM, Jakub Kicinski wrote:
On Fri, 10 Jan 2025 10:07:18 +0100 Daniel Sedlak wrote:Hello, I am writing an affinity scheduler in the userspace for network cards's Tx/Rx queues. Is there a generic way to retrieve all IRQ numbers for those queues for each interface? My goal is to get all Tx/Rx queues for a given interface, get the IRQ number of the individual queues, and set an affinity hint for each queue. I have tried to loop over /proc/interrupts to retrieve all queues for an interface in a hope that the last column would contain the interface name however this does not work since the naming is not unified across drivers. My second attempt was to retrieve all registered interrupts by network interface from /sys/class/net/{interface_name}/device/msi_irqs/, but this attempt was also without luck because some drivers request more IRQs than the number of queues (for example i40e driver).We do have an API for that https://docs.kernel.org/next/networking/netlink_spec/netdev.html#napi but unfortunately the driver needs to support it, and i40e currently doesn't:
Thank you for the link, I somehow missed that part of netlink…
$ git grep --files-with-matches netif_napi_set_irq drivers/net/ethernet/amazon/ena/ena_netdev.c drivers/net/ethernet/broadcom/bnxt/bnxt.c drivers/net/ethernet/broadcom/tg3.c drivers/net/ethernet/google/gve/gve_utils.c drivers/net/ethernet/intel/e1000/e1000_main.c drivers/net/ethernet/intel/e1000e/netdev.c drivers/net/ethernet/intel/ice/ice_lib.c drivers/net/ethernet/intel/igc/igc_main.c drivers/net/ethernet/mellanox/mlx4/en_cq.c drivers/net/ethernet/mellanox/mlx5/core/en_main.c drivers/net/ethernet/meta/fbnic/fbnic_txrx.c Should be easy to add. Let me CC the Intel list in case they already have a relevant change queued for i40e..
Thank you for directions, will check Intel's mailing list and poke around with implementing that.
Daniel
